Question

And I have some question about 3.1, it says "3.1 Your app must use only APIs for Metro style apps"

Is this "only" totally restrictive? Say for instance that i have an existing web app that i want to port. I do XHR using a library (say jQuery or Google Closure Library in my case). If i want to port my webapp to a Metro app, should i use WinJS.xhr instead
or can i keep using my library for that?

Same goes for DOM manipulation.

Could i get some clarifications about it and how restrictive this rule is? Can i use external JS libraries freely or that would get me rejected from the Windows Store?